1. Field of the Invention
The present invention relates to a bicycle rear hub mounted to a rear part of a bicycle frame.
2. Background Information
Bicycling is becoming an increasingly more popular form of recreation as well as a means of transportation. Moreover, bicycling has become a very popular competitive sport for both amateurs and professionals. Whether the bicycle is used for recreation, transportation or competition, the bicycle industry is constantly improving the various components of the bicycle as well as the frame of the bicycle. One component that has been extensively redesigned is the rear hub of the bicycle.
The rear hubs of bicycles, particularly the rear hubs used on “light roadster” bicycles in which the sprocket is mounted such that it can be detached and reattached freely, are generally provided with the following: a hub shaft mounted in a non-rotatable manner to a rear part of the bicycle frame; a hub shell mounted in a freely rotatable manner to the hub shaft; a drive body mounted in a freely rotatable manner to one end of the hub shell; a one-way clutch arranged between the drive body and the hub shell and configured to transmit rotation from the drive body to the hub shell in one direction; and a sprocket mounted to a radially outward-facing surface of the drive body such that it can neither rotate nor move axially with respect to the drive body.
Axially-extending interlock grooves for mounting the sprocket in a non-rotational manner are arranged in the radially outward-facing surface of the drive body with circumferential spacing there-between. The sprocket is prevented from coming out of place by an annular spring member mounted to the radially outward-facing surface of the drive body. The spring member is made of a piece of elastic steel wire curved into a C shape and mounted into an annular groove formed in the radially outward-facing surface of the drive body. A seal member for preventing contaminants from invading the bearing unit is provided between the drive body and the bearing unit.
In the conventional arrangement just described, axially-extending interlock grooves are formed in the radially outward-facing surface of the drive body and an annular groove is also formed in the surface and installed with a spring member. With a plurality of groves formed and a spring member mounted in its radially outward-facing surface, the external appearance of the drive body is unattractive. Also, since the radially outward-facing surface is exposed, there is the risk that in some environments the drive body and the spring member mounted thereto will corrode.
In view of the above, it will be apparent to those skilled in the art from this disclosure that there exists a need for an improved rear hub. This invention addresses this need in the art as well as other needs, which will become apparent to those skilled in the art from this disclosure.